The present invention relates to desk-top copiers generally and specifically to such copiers employing gaseous ammonia as a developing media and is adaptable to all copiers employing a noxious gas which can be stripped by absorption, adsorption or reaction with another media.
One of the principal disadvantages of copiers employing ammonia is the necessity for complex ventilating systems which discharge the effluent developer gas to the outside of the building in which the copier is being used. Such installations are both costly and unsuited for use as desk-top or portable copiers.
The principal object of the present invention is to provide an efficient yet simple and inexpensive scavenging system for removing substantial amounts of effluent ammonia escaping both from the developing chamber as well as entrained on or clinging to the developed copy, circulating the scavenged gas through a stripping bath and returning it to the surface of the developed copy. The scavenging system above-described is coupled with a primary ammonia developing gas circulating system which circulates ammonia from a source of supply to the developing chamber and from thence back to the source of supply for recirculation.
Such a system is able to draw make-up air from both the primary and secondary circulation systems for use as a working media, entrain ammonia into it in the primary system, and strip enough of the ammonia in the secondary system to permit discharge to room air. Additionally, the scavenging system removes ammonia clinging to the developed copy as well as leading from the developing chamber and passes it through the stripping bath with the working media. For still further efficiency, the effluent from the stripping bath, if reactive with the developer gas, such as citric acid with ammonia, can be returned to and distributed over the developed copy downstream from the vacuum scavenger manifold where the partial pressure of the reactive stripping media further neutralizes the developer gas (ammonia) still clinging to the developed copy.